Gas treating solutions containing imidazole-amine compounds and methods of making the same

Abstract

Systems comprising a composition where an imidazole is tethered to an amine and a solvent are described herein. Methods of their preparation and use are also described herein. The methods of using the systems include the reduction of volatile compounds from gas streams and a liquid stream.

What is claimed is: 
     
       1. A method of reducing one or more volatile compounds from a stream, comprising:
 contacting a stream with a solution consisting of an imidazole having formula (I) or a salt thereof, and a solvent, 
 
       
         
           
           
               
               
           
         
         wherein 
         R is selected from null, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy; wherein R is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; and 
         R 1  and R 2  are, independent of one another, hydrogen, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; wherein each R 1  or R 2  independent of each other is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl;
 R 3  is selected from hydrogen, C 1 -C 10  alkyl, C 1 -C 10  alkoxy, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6  C 14  aryloxy, wherein R 3  is optionally substituted with C 1 -C 10  alkyl, C 1 -C 10  alkoxy, C 2 -C 10  alkenyl, C 2 -C 10  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; 
 R 4  and R 5  are each independent of the other, selected from hydrogen, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; wherein each R 1  or R 2  independent of each other is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; or wherein 
 R 4  and R 5  together form a 6 membered aromatic ring containing 6 carbon atoms, wherein the solvent consists essentially of water. 
 
       
     
     
       2. The method of  claim 1 , wherein the imidazole of formula (I) forms at least one complex with the one or more volatile compounds, and wherein the method further comprises removing the at least one complex from the stream. 
     
     
       3. The method of  claim 1 , wherein the imidazole of formula (I) is non-ionic under neutral conditions. 
     
     
       4. The method of  claim 1 , wherein the one or more volatile compounds present in the stream comprise one or more of carbon dioxide, hydrogen sulfide, sulfur dioxide, nitrogen oxide, nitrogen dioxide, carbonyl sulfide, or carbon disulfide. 
     
     
       5. The method of  claim 1 , wherein R is selected from —CH 2 —, —CH(CH 3 )—, —C(CH 3 ) 2 —, —CH 2 CH 2 —, —CH 2 CH(CH 3 )—, —CH 2 C(CH 3 ) 2 —, —CH 2 CH 2 CH 2 , —CH 2 CH 2 CH(CH 3 )—, or —CH 2 CH 2 C(CH 3 ) 2 —. 
     
     
       6. The method of  claim 1 , wherein the imidazole of formula (I) is selected from 
       
         
           
           
               
               
           
         
       
     
     
       7. The method of  claim 1 , wherein the imidazole of formula (I) is present in the solution in an amount from about 30 wt % to about 70%. 
     
     
       8. The method of  claim 4  wherein when the volatile compound is carbon dioxide, the imidazole of formula (I) absorbs carbon dioxide in a ratio of 1:3. 
     
     
       9. A method for sweetening a natural gas feed stream, comprising:
 a) contacting the natural gas feed stream with a solution consisting of an imidazole of formula (I) or a salt thereof, and a solvent, 
 
       
         
           
           
               
               
           
         
         wherein 
         R is selected from null, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy; wherein R is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; and 
         R 1  and R 2  are, independent of one another, hydrogen, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; wherein each R 1  or R 2  independent of each other is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl;
 R 3  is selected from hydrogen, C 1 -C 10  alkyl, C 1 -C 10  alkoxy, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy, wherein R 3  is optionally substituted with C 1 -C 10  alkyl, C 1 -C 10  alkoxy, C 2 -C 10  alkenyl, C 2 -C 10  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; 
 R 4  and R 5  are each independent of the other, selected from hydrogen, C 1-20  alkyl, C 2-20  alkenyl, C 1 -C 20  alkoxy, C 2-20  alkynyl, C 1-20  heteroalkyl, C 2-20  heteroalkenyl, C 2-20  heteroalkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, C 6 -C 14  aryloxy, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; wherein each R 1  or R 2  independent of each other is optionally substituted with C 1 -C 20  alkyl, C 1 -C 20  alkoxy, C 2 -C 20  alkenyl, C 2 -C 20  alkynyl, C 6 -C 14  aryl, C 1 -C 13  heteroaryl, amino, carbonyl, ester, ether, halide, carboxyl, hydroxy, nitro, cyano, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, thiol, or phosphonyl; or wherein 
 R 4  and R 5  together form a 6 membered aromatic ring containing 6 carbon atoms, 
 wherein the solvent consists essentially of water; 
 
         b) forming a purified gas feed stream and a gas-rich solution; and 
         c) separating the purified gas feed stream and the gas-rich solution. 
       
     
     
       10. The method of  claim 9 , wherein the imidazole of formula (I) is non-ionic under neutral conditions. 
     
     
       11. The method of  claim 9 , wherein the natural gas feed stream comprises one or more volatile compounds comprising one or more of carbon dioxide, hydrogen sulfide, sulfur dioxide, nitrogen oxide, nitrogen dioxide, carbonyl sulfide, or carbon disulfide. 
     
     
       12. The method of  claim 11 , wherein in step b) the one or more volatile compounds are transferred to the gas-rich solution. 
     
     
       13. The method of  claim 11 , wherein the one or more volatile compounds form at least one complex with the imidazole of formula (I). 
     
     
       14. The method of  claim 9 , wherein R is selected from —CH 2 —, —CH(CH 3 )—, —C(CH 3 ) 2 —, —CH 2 CH 2 —, —CH 2 CH(CH 3 )—, —CH 2 C(CH 3 ) 2 —, —CH 2 CH 2 CH 2 , —CH 2 CH 2 CH(CH 3 )—, or —CH 2 CH 2 C(CH 3 ) 2 —. 
     
     
       15. The method of  claim 9 , wherein the imidazole of formula (I) is selected from 
       
         
           
           
               
               
           
         
       
     
     
       16. The method of  claim 9 , wherein the imidazole tethered to an amine is present in the solution in an amount from about 30 wt % to about 70 wt %. 
     
     
       17. The method of  claim 1  wherein the imidazole of formula (I) is present in the solution in an amount from about 50 wt % to about 90 wt %. 
     
     
       18. The method of  claim 9  wherein the imidazole of formula (I) is present in the solution in an amount from about 50 wt % to about 90 wt %. 
     
     
       19. The method of  claim 1 , wherein the imidazole having formula (I) is a basic salt. 
     
     
       20. The method of  claim 1 , wherein the imidazole having formula (I) is an alkali salt. 
     
     
       21. The method of  claim 1 , wherein the imidazole having formula (I) is a sodium salt. 
     
     
       22. The method of  claim 9 , wherein the imidazole having formula (I) is a basic salt. 
     
     
       23. The method of  claim 9 , wherein the imidazole having formula (I) is an alkali salt. 
     
     
       24. The method of  claim 9 , wherein the imidazole having formula (I) is a sodium salt.